After two games on the DSiWare service, Teyon's Robot Rescue series, famous for fiendishly difficult maze puzzles and a unique synchronized movement mechanic, has made the jump to the 3DS eShop with this latest instalment, Robot Rescue 3D. Rather than an entirely new entry in the series, Robot Rescue 3D is a compilation that includes remastered versions of the first two Robot Rescue titles, as well as twenty new eShop-exclusive levels. It's the best Robot Rescue yet, and a great starting point for new recruits, but the déjà-vu might be too much for returning rescuers.

From the title screen, players can choose to play either Robot Rescue, Robot Rescue 2 or the twenty new levels — somewhat confusingly labelled as "Robot Rescue 3D" — and the core gameplay of all three games revolves around guiding buck-toothed, blob-like 'bots to safety through obstacle-filled mazes. The catch which makes their rescue more interesting — and way more challenging — is that you control every robot on the board at once. Press right on the D-Pad, for instance, and they'll all shuffle to the right. The synchronized movement, combined with the mines, doors, switches, conveyor belts, teleporters and barriers that populate the mazes, makes for some seriously devious puzzles. From Robot Rescue 2 on, there's also a colour mechanic that further complicates things, with panels to paint the robots, and doors, barriers, and other elements that only apply to droids of a certain shade.

The first few levels of Robot Rescue and Robot Rescue 2 serve as tutorials to help get you up to speed, but things get dicey very quickly; these puzzles are complex, multi-step affairs that require plenty of advance planning — or lots of trial and error — to solve. They can also sometimes feel tedious rather than clever, inspiring an "Ugh" as often as an "Aha!" upon completion; hardcore puzzle-fans will have a field day, but casual dabblers will find themselves frustrated. Thankfully, instant restarts help move things along, and the versions of Robot Rescue and Robot Rescue 2 included here have seen some welcome gameplay tweaks from their DSiWare days.

For a start, both titles originally used a "book-view" presentation with the system held sideways, which didn't always mesh well with the games' precision puzzling, and often left robots in the uneasy abyss of the DSi's hinge. Here, all the action takes place on the 3DS' top screen, making for a much smoother experience. Along with the screen shift comes the ability to use either the D-Pad or the face buttons to control your mechanical minions, though the lack of Circle Pad support is an odd omission.

Perhaps the best change to the Robot Rescue formula is the addition of the Golden Keys, which allow you to skip over particularly problematic puzzles. You'll start with three Keys (shared across all three games), and you can earn more by going back to complete the puzzles you skipped. This makes a huge difference; one of our biggest complaints with Robot Rescue 2 was the erratic difficulty that could leave you stuck on one puzzle for hours, only to breeze through the next few. The difficulty spikes are still there, but being able to save trickier puzzles for later — along with the fact that there are three separate sets of levels this time — means there's always something to do when you sit down to play, and that's a big improvement from the original games.

The Golden Keys are especially welcome in the twenty new levels, where there isn't so much a difficulty curve as a difficulty plateau — at high elevation. Here, there's no tutorial, no introductory level, and no mercy — the first stage comes out swinging with a conveyor-belt puzzle where success hinges on (among other things) holding a certain direction on the D-Pad as soon as it starts. It's actually an apt introduction to this level set, because — unless you happen to be clairvoyant — your first attempt will end in failure by design. These levels are extremely tough, taking every trick in the book from the first two games and combining them into puzzles that will either delight or frustrate to no end, depending on your disposition.

No matter how long they take you to complete, however, twenty levels is a small offering compared to the first two games — there are forty-five stages in Robot Rescue and sixty in Robot Rescue 2 — and that's the biggest problem with this collection. It certainly won't bother new players, but if you've already played the previous two titles and were hoping for a similarly lengthy adventure here, having fewer than two dozen new puzzles to solve is a let-down.

Like its predecessors, Robot Rescue 3D goes for brainteasers over beauty, and its presentation is rather bland as a result. Whether the cartoony robot designs appeal or not will be down to individual taste, but either way, the game shows its DSiWare roots with recycled, repetitive assets and backgrounds. That said, the titular 3D effect looks great, adding a nice layer of depth that makes the otherwise dull backgrounds more interesting — there's even a faux-3D look to the robots, created with layered sprites. The soundtrack's mechanical melodies are a great fit for the theme, and innocuous enough that they won't get on your nerves, even when the puzzles do.

Conclusion

Robot Rescue 3D doesn't reinvent the series; it repackages it. With remastered versions of Robot Rescue and Robot Rescue 2, and a new twenty-stage level pack, this is the best way for new players to get in on these games' unique, brain-bending puzzles, and the graphical and gameplay tweaks from the originals make it the definitive Robot Rescue package. Some puzzles can frustrate, and the relatively small amount of new content makes it harder to recommend for players who've rescued these robots before, but if this is your first robo-rodeo and you're up for a serious challenge, these might just be the droids you're looking for.